Cyclically operated switch control apparatus



Oct. 29, 1963 H. s. LEWIS ETAL 3,109,073

CYCLICALLY OPERATED SWITCH CONTROL APPARATUS Filed May 12, 1961 United States Patent Ofiice 3 ,109,073 Patented Oct. 29, 1963 3,109,073 CYCLICALLY OPERATED SWITCH CONTROL APPARATUS Harry Stanley Lewis and Francis McGuirk, Birmingham,

England, assignors to Chamberlain & Hookham Limited, Birmingham, England Filed May 12, 1961, Ser. No. 109,592 3 Claims. (Cl. 200-38) This invention relates to cyclically operated switch control apparatus of the kind in which a plurality of electric switches are operated in a predetermined cycle by means of a plurality of rotatable cams or like members.

One form of such apparatus is described in our copending patent application Serial No. 109,630, and is intended, in one application, for use in controlling the sequence and duration of operations carried out in a machine such as a domestic, electrically operated washing machine, although it is to be understood that the apparatus can also be used for analogous purposes. In operating Washing machines and other machines designed to carry out a cycle of operations, it may at times be desirable to modify the cycle so that, for example, some operations are eliminated or speeded up. Normally, the rotatable cams or like members (which are conveniently mounted on a common shaft) are rotated by means of power-operated means such as an electric motor at a predetermined constant speed but if it is desired to modify the normal cycle, speed-varying means are employed which can be used to alter the speed of rotation of the cams over selected parts of the cycle. Thus, an auxiliary motor may be provided which is adapted to drive the rotatable cams and which is put into operation over selected parts of the cycle to increase the speed of said cams. Alternatively, the original cam driving motor may be used with a modified circuit arrangement or with modified gearing.

The object of the present invention is to provide a new or improved construction in which speed-changing means can be operated in an efficient and safe manner.

In accordance with the invention there is provided switch control apparatus having a shaft on which is mounted a plurality of cams arranged to operate a plurality of switches, said shaft being adapted to be rotated by power-operated driving means at a predetermined constant speed for normal operation and, through the intermediary of speed-varying means, at a speed different from the normal speed, there being also provided a selector member or members for effecting operation of the speed-varying means over a selected part of the cycle and interlocking means operable by said shaft on commence ment of a cycle of operations to lock said selector member or members and prevent any further movement thereof until the cycle has been completed.

Where said selector member or members is or are arranged for manual operation there may be provided a second shaft which is arranged in a spaced parallel relationship relative to the shaft on which the cams are mounted, said second shaft being connected to the selector member or members so as to be rotatable thereby. In this case said second shaft may be provided with a notched plate which is engageable by a locking member to prevent rotation of said second shaft, said locking member being moveable by a cam mounted on or rotatable with the first-mentioned shaft.

The invention will now be more particularly described with reference to the accompanying drawing which shows schematically one example of switch control apparatus in accordance with the present invention.

Referring to the drawing, the apparatus shown therein is in one application designed for use in a domestic electrically operated washing machine and may be constructed as described in our above mentioned co-pending patent application Serial No. 109,630.

Thus the apparatus is provided with a first shaft 10 on which are mounted a plurality of disc-like cams 11 arranged to operate a plurality of switches 12 on rotation of said first shaft. The first shaft is adapted to be rotated at a predetermined constant speed during a normal cycle of operations by means of power-operated driving means in the form of an electric motor 13. In some circumstances, however, it may be desired to modify the normal cycle by eliminating or speeding up some of the various operations. To this end there is provided speed-varying means in the form of an auxiliary motor 14 which is adapted to rotate the cam-carrying shaft at a speed which is different from the normal speed of rotation during a normal cycle in the manner described in our above mentioned co-pending application Serial No. 109,630 as aforesaid.

The auxiliary motor 14 is energised through the intermediary of a selector switch or selector member 15 which is mounted on a second shaft 16 which extends in a spaced parallel relationship relative to the first shaft 10. Each of said shafts is provided with an arm 17 which carries a set of brushes 18 and associated with each set of brushes are a plurality of conductors generally indicated by reference numeral 19 which extend in circular or part-circular paths around the associated shaft. Some at least of the conductors associated with one set of brushes are electrically connected to some at least of the conductors associated with the other set of brushes and the arrangement is such that current fed to the conductors or one of the conductors associated with the sec and shaft 16 will be picked up by the brushes associated with said first shaft 10 when these brushes are in a predetermined angular position or whilst they pass through a predetermined arc of movement owing to the rotation of said first shaft. Thus the position at which the first set of brushes will pick up current (such current being used to energise the auxiliary motor 14) will be determined by the position of the second set of brushes rotatable with the second shaft 16, which position is in turn selected by the selector switch or selector member 15.

The first shaft 10 is also provided with a cam plate 20 having a notch 21 which receives one end of a springloaded locking member 22 when said first shaft is in its initial position prior to the commencement of a cycle of operations. The other end of said locking member is engageable with a notched plate 23 mounted on the second shaft 16, there being as many notches in said notched plate 23 as there are stations associated with the selector member 15. When the selector member is turned to any particular station one of the notches in the notched plate 23 will be aligned with the adjacent end of the locking member 22. If the apparatus is now put into operation commencement of rotation of the first shaft will result in the locking member being pivoted against the force exerted by spring 24 as the notch 21 in the plate 20 mounted on said first shaft disengages from the adjacent end of said locking member so that its opposite end enters into the aligned notch of the notched plate 23 on the second shaft. This will effectively prevent any further movement of the selector member 15 until the cycle has been completed and the first shaft returned to its initial position. Any damage to the apparatus which might otherwise be caused by an attempt to modify the cycle whilst the apparatus is in operation, is thus avoided.

In an alternative construction the selector member 15 may be operated by remote control as, for example, by means of a series of push-buttons together with a homing motor. In this case the locking member may be dispensed with and the first shaft 10 may carry a cam or projection which is adapted to operate a switch or cut-out so as to isolate the homing motor as soon as rotation of the first shaft commences. Thus the homing motor can only be operated whilst the first shaft is at rest in its initial position prior to commencement of a cycle of operations.

Having thus described our invention what We claim as new and desire to secure by Letters Patent is:

1. Switch control apparatus comprising in combination a rotatable shaft, a plurality of cams rigidly mounted in axially spaced relationship on said shaft so as to be rotatable therewith for operating a plurality of switches, poweropenable means connected to said shaft for imparting rotation thereto at a normal predetermined constant speed, speed-varying means under the control of which said shaft is rotatable at a speed different from said normal prede-' termined constant speed, selector means under the control of which said speed-varying means is actuable, and means operable by said shaft for preventing actuation of said speed-varying means during a predetermined rotational movement of said shaft.

2. Switch control apparatus according to claim 1, and having a second rotatable shaft which is mounted in spaced and parallel relationship to the first mentioned shaft, said selector means being connected to said second shaft.

3. Switch control apparatus according to claim 2, wherein the means for preventing actuation of said speedvarying means comprises in combination an additional cam secured to, and rotatable with, the first mentioned shaft, a notched plate secured on said second shaft, and a locking member movable by said additional cam into engagement with said notched plate to prevent rotation of said second shaft.

References Cited in the file of this patent UNITED STATES PATENTS 2,870,834 Si'sson Jan. 27, 1959 

1. SWITCH CONTROL APPARATUS COMPRISING IN COMBINATION A ROTATABLE SHAFT, A PLURALITY OF CAMS RIGIDLY MOUNTED IN AXIALLY SPACED RELATIONSHIP ON SAID SHAFT SO AS TO BE ROTATABLE THEREWITH FOR OPERATING A PLURALITY OF SWITCHES, POWER OPERABLE MEANS CONNECTED TO SAID SHAFT FOR IMPARTING ROTATION THERETO AT A NORMAL PREDETERMINED CONSTANT SPEED, SPEED-VARYING MEANS UNDER THE CONTROL OF WHICH SAID SHAFT IS ROTATABLE AT A SPEED DIFFERENT FROM SAID NORMAL PREDE- 